EnergyPlus: Thermal mass of ducts?

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I have observed significantly faster transient heating/cooling behavior in EnergyPlus models, compared to data from real buildings, and identified the thermal inertia of the ducts as the most likely cause.

Is there a way to add thermal mass to the connections from the heating/cooling plant to the rooms in EnergyPlus?

There seems to be no such property here: https://bigladdersoftware.com/epx/doc...